UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

 REGION IX AIR DIVISION 

Technical Support Document for EPA’s Direct Final Rulemaking for the 

California State Implementation Plan 

Ventura County Air Pollution Control District, Rule 74.13, Aerospace Assembly and Component 

Manufacturing Operations 

Prepared by Nancy Levin, April 7, 2014 
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RULE IDENTIFICATION 

Agency: Ventura County Air Pollution Control District (VCAPCD)

SIP-Approved Rule: Rule 74.13, Aerospace Assembly and Component Manufacturing 

Operations; Adopted – 4/15/86; Revised 10/13/87, 1/22/91, 9/10/96, 11/11/03; 

Submitted – 4/26/05; Approved – 10/25/2005 (70 FR 6156) 

Subject of this TSD: Rule 74.13, Aerospace Assembly and Component Manufacturing 

Operations; Amended – 9/11/12; Submitted – 4/22/13 

RULE SUMMARY - Rule 74.13 establishes reactive organic compound (ROC) limits for 

industrial sites engaged in the manufacturing, assembling, coating, masking, bonding, paint 

stripping, and surface cleaning of aerospace components and the cleanup of equipment associate with 

these operations. It also describes related recordkeeping requirements and test methods. 

This rule does not apply to coating or cleaning of metal parts, including tooling operations, 

which are covered by Rule 74.12. Ventura County APCD Rule 74.12 "Surface Coating of Metal 

Parts and Products" was approved into the State Implementation Plan (SIP) on May 24, 2011 

(76 FR 30025). 

Changes from the approved SIP rule include the following: 

1. Section B.2 – This section's name was changed from “Surface and General Cleaning” to 

"Solvent Cleaning” to be consistent with the definition in VC 74.61

 "Surface Cleaning 

and Degreasing". 

2. Section B.2.b.2 – This section reduces the limit for the composite partial pressure of 

solvent cleaners from 45 to 5mm Hg at 20o

C. It requires solvent cleaners to be less than 

5mm Hg at 20o

C or limits the ROG content to 25 grams per liter or less. 

3. Section B.4 – This section changed the requirements for “Storage of ROC Containing 

Materials,” making them more enforceable and consistent with VC Rule 74.12.2 

4. Section B.5.e – This section added a requirement that if a spray gun is used, the user shall 

demonstrate that it meets the definition of high volume low pressure (HVLP) (section 

G.27) in design and use. It requires HVLP equipment to be identified by test air cap 

measurements or an inlet pressure measurement as specified in section G.27. 

5. Section B.5.f – This section was changed by deleting the requirement for other 

application methods to demonstrate achievement of 65% transfer efficiency. Rather, it 

allows for any other alternative method that achieves a transfer efficiency “equivalent to, 

or higher than one of the application methods listed” in sections B.5.a through B.5.e. It 

requires prior written approval of the APCO for each alternative method. Section E.6 

specifies the South Coast Air Quality Management District test method to determine 

transfer efficiency. 

                                                            

1

 VC 74.6 was adopted on 11/11/03 and approved by EPA on 10/25/2005 (70 FR 61561). 

2

 VC 74.12 was adopted on 4/8/08 and approved by EPA on 5/24/11 (76 FR 30025).  
2

6. Section B.6 – Clarified that written approval in the form of an Authority to Construct and 

Permit to Operate is required for using the “Add-on Control Equipment Option.” 

7. Section B.10 – Requires that the ROG content of low-solids adhesives, coatings, primers 

or sealants in section B.1 be expressed in grams/liter of material. 

8. Section C.2 – Exemptions were revised. 

9. Section D – Recordkeeping was reformatted and reworded to be consistent with VC Rule 

74.123

10. Section E – Test Methods were updated. 

11. Section G – Definitions were added for “Capture Efficiency,” “Degreaser,” “Low-Solids 

Adhesive, Coating, Primer or Sealant,” and “Solvent Cleaning.” Changes to other 

definitions increased their specificity. Definitions were renumbered. 

RULE EVALUATION CRITERIA - We primarily used the following criteria to evaluate the 

submitted rule: 

1. Enforceability – Section 110(a)(2)(A) of the Clean Air Act (CAA) requires that 

regulations submitted to EPA for incorporation into the SIP must be clear and legally 

enforceable. The Bluebook (Issues Relating to VOC Regulation Cutpoints, 

Deficiencies, and Deviations, EPA, May 25, 1988) and the Little Bluebook 

(Guidance Document for Correcting Common VOC & Other Rule Deficiencies, EPA 

Region 9, August 21, 2001) were used to help evaluate compliance with the CAA 

§110(a)(2)(A) requirement for enforceability. 

2. Stringency – CAA section 172(c)(1) specifies that SIPs for nonattainment areas must 

include reasonably available control technology (RACT) for sources of emissions. 

Section 182(b)(2) specifically provides that for nonattainment areas classified as 

moderate or worse, states must revise their SIP to include RACT for sources of VOC 

emissions covered by a Control Techniques Guidelines (CTG) document issued after 

November 15, 1990 and prior to the area’s date of attainment. 

3. Non-interference – CAA §110(l) prohibits EPA from approving any SIP revision that 

would interfere with any applicable requirement concerning attainment and 

reasonable further progress (RFP) or any other applicable requirement of the CAA. 

The VCAPCD regulates an area that is classified as nonattainment (serious) for the 1997 and 

2008 8-hour Ozone standards. 

We used EPA’s CTGs titled Control of Volatile Organic Compound Emissions from Coating 

Operations at Aerospace Manufacturing and Rework Operations (EPA-453/R-97-004, 

December 1997) (hereinafter “Aerospace CTG”) and 40 C.F.R. 63 Subpart GG – National 

Emission Standards for Aerospace Manufacturing and Rework Facilities (hereinafter "Aerospace 

NESHAP") to evaluate this rule. In addition, we reviewed other state and local rules for this 

source category. 

                                                            

3 Ibid.
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RULE EVALUATION 

1. Enforceability – The recordkeeping requirements for coatings and control system

parameters, test methods and other requirements generally ensure that the submitted 

rule can be enforced. They include records of usage of compliant and noncompliant 

materials, records of key operating parameters and records for those claiming an 

exemption for de minimis usage. Therefore, we propose to determine that submitted 

Rule 74.13 is sufficiently clear and enforceable. 

2. Stringency – The VCAPCD has stated that sources subject to this rule in the District are 

below the CTG's threshold of 25 tons per year potential to emit and therefore, are not 

subject to RACT.4

 However, while VCAPCD has stated that these sources are not 

subject to RACT and its demonstration seems sufficient, based on our review of the 

Aerospace CTG, Aerospace NESHAP, and other state and local rules for this source 

category, we believe Rule 74.13 could be further strengthened. Please see “Additional 

Recommendations” for details. 

3. Non-interference - We believe the submitted rule is more stringent than the version 

previously approved into the SIP, and therefore this rule would not interfere with any 

applicable requirement concerning attainment and reasonable further progress (RFP) 

or any other applicable requirement of the CAA. 

RULE DEFICIENCIES – We have not identified deficiencies in submitted Rule 74.13 

sufficient for EPA to propose less than full approval.

ADDITIONAL RECOMMENDATIONS FOR THE NEXT RULE REVISION – The 

following revisions are not currently the basis for rule disapproval, but are recommended for the 

next time the rule is amended. If, in the future, existing sources become major sources of VOC 

emissions, or new sources locate in the District, the District will need to amend the rule to meet 

RACT requirements. In particular, Rule 74.13 does not contain limits for all the Aerospace CTG 

categories. In addition, the exemptions in the rule appear to be less stringent than in the 

Aerospace CTG Appendix B: Aerospace Manufacturing and Rework Operations Model Rule 

(Model Rule). 

Add VOC categories and coating limits 

The VOC limit table of Rule 74.13 does not include the following specialty coating categories 

that are provided in the CTG. Rule 74.13 should be updated to include the following categories 

and limits updated to meet current RACT levels the next time the rule is amended. 

1. Ablative Coating 

                                                            

4 Draft Ventura County Air Pollution Control District 2014 Reasonably Available Control Technology (RACT) 

State Implementation Plan (SIP) Revision April 2, 2014, pp. 32-33.
4

2. Commercial Interior Adhesive 

3. Cyanoacrylate Adhesive 

4. Rocket Motor Bonding Adhesive 

5. Rubber-based Adhesive 

6. Bearing Coating 

7. Caulking and Smoothing Compounds 

8. Chemical Agent-Resistant Coating 

9. Clear Coating 

10. Commercial Exterior Aerodynamic Structure Primer 

11. Compatible Substrate Primer 

12. Corrosion Prevention Compound 

13. Cryogenic Flexible Primer 

14. Cryoprotective Coating 

15. Electrostatic Discharge and Electromagnetic Interference (EMI) Coating 

16. Elevated-Temperature Skydrol-Resistant Commercial Primer 

17. Epoxy Polyamide Topcoat 

18. Flexible Primer 

19. Insulation Covering 

20. Intermediate Release Coating 

21. Lacquer 

22. Bonding Maskant 

23. Critical Use and Line Sealer Maskant 

24. Seal Coat Maskant 

25. Metalized Epoxy Coating 

26. Mold Release 

27. Part Marking Coating 

28. Rocket Motor Nozzle Coating 

29. Screen Print Ink 

30. Extrudable/Rollable/Brushable Sealant 

31. Sprayable Sealant 

32. Silicone Insulation Material 

33. Specialized Function Coating 

34. Thermal Control Coating 

35. Wet Fastener Installation Coating 

Clarify or Revise Exemptions

1. Rule 74.13 allows an exemption when “No complying coating or adhesive is available,” 

which is not provided for in the CTG. Please clarify the criteria used to make this 

determination (e.g., not available within the District v. not sold in the U.S.). 

2. The model rule contained in the Aerospace CTG allows an exemption for facilities that 

use separate formulations of coatings in volumes of less than 50 gallons per year, subject 

to a maximum exemption of 200 gallons per year. Rule 74.13 includes a maximum 

exemption of 200 gallons for facilities that use separate formulations of coatings in 

volumes of less than 20 gallons per year. However, Rule 74.13 appears to allow 
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unlimited use of separate formulations of adhesives in volumes of less than 10 gallons. 

When the rule is revised, we recommend that the District clarify how these exemptions 

are at least as stringent as the model rule, or revise the rule to be at least as stringent as 

the model rule. 

EPA ACTION - EPA staff recommends approval of Rule 74.13 pursuant to CAA §110(k) (4) 

and §301(a). 

REFERENCES 

1. “Issues Relating to VOC Regulation Cutpoints, Deficiencies, and Deviations,” (a.k.a., 

Bluebook) EPA OAQPS, May 25, 1988 

(http://www.epa.gov/ttn/naaqs/ozone/ozonetech/voc_bluebook.pdf). 

2. “Guidance Document for Correcting Common VOC & Other Rule Deficiencies,” (a.k.a., 

Little Bluebook), EPA Region 9, August 21, 2001 

(http://www.epa.gov/region09/air/sips/littlebluebook2001.pdf) 

3. State Implementation Plans; General Preamble for the Implementation of Title I of the 

Clean Air Act Amendments of 1990, 57 FR 13498 (April 16, 1992); 57 FR 18070 (April 

28, 1992). 

4. CTG for Control of Volatile Organic Compounds (VOC) from Coating at Aerospace 

Manufacturing and Rework Facilities EPA-453/R-97-004, December 1997 

5. 40 C.F.R. 63 Subpart GG – National Emission Standards for Aerospace Manufacturing 

and Rework Facilities 

6. VCAPCD Rule 74.13 – Aerospace Assembly and Component Manufacturing Operations, 

September 11, 2012. 

7. VCAPCD Rule 74.13 – Aerospace Assembly and Component Manufacturing Operations, 

as approved into the SIP on October 25, 2005 (70 FR 6156).